McIntosh MA6850 User manual

MA6850/MA6800 Integrated Amplifiers

See “SYSTEMS ENGINEERING”
in main brochure for more on
McIntosh system architectures.
MA6850/MA6800
Integrated Amplifiers
Featured Technologies
EXCLUSIVE MCINTOSH OUTPUT AUTOFORMERS. An impedance mismatch between a power
amplifier and a loudspeaker can cause distortion and a reduction in power. The legendary
McIntosh autoformer is a hand-crafted transformer with output connections for 2, 4, and 8 ohms,
allowing an ideal impedance match between amp and speaker. A McIntosh amplifier with an
autoformer can also safely drive multiple speakers connected in parallel without shortening
the life of the output stage. There is absolutely no performance penalty with an autoformer. In
fact, its frequency response exceeds that of the output circuit itself, and extends well beyond
the audible range. Distortion is so low it is virtually immeasurable.
EXCLUSIVE MCINTOSH POWER ASSURANCE SYSTEM. Power Assurance is a collection of
technologies that enhance performance and reliability and protect the amp and the loudspeakers.
Power Guard®clipping protection. Power Guard ensures that the amplifier will always
deliver full power without causing clipping distortion. If an amplifier channel is overdriven,
Power Guard automatically reduces the input volume just enough to keep distortion below 2%
and prevent any clipping distortion. Thanks to an optical resistor, Power Guard acts literally at
the speed of light, producing absolutely no audible side effects. An amplifier with Power Guard
will actually deliver clipping-free output well above its rated power.
Sentry Monitor®current protection. Sentry Monitor continually senses the voltage and current
of the output stage and confines it to a safe limit. Sentry Monitor does not limit power output.
Thermal Cutout. If the cooling air is blocked and the power transistors become too hot,
thermal cutouts protect against overheating until the amp cools.
DC Failure protection. In the rare event of an output circuit failure, any DC current that appears
in the output is shunted to ground by the autoformer, protecting the loudspeakers from damage.
Turn-On Delay. This circuit delays operation for about two seconds after turn-on in order to
avoid any pops or thumps generated as other equipment turns on.
Soft Start inrush protection. Thermistors in the power transformer act as a cushion against
inrush current, eliminating component stress during turn-on. Soft Start is one of many design
details that contribute to the remarkable longevity of McIntosh equipment.
ILLUMINATED PEAK-RESPONDING METERS. McIntosh meters respond 95% full scale to a
single-cycle tone burst at 2kHz. Response is almost 10-times faster than a professional VU meter.
Those considering a McIntosh system for the first time will find integrated
amplifiers a comfortable place to start. In virtually every respect the MA6850
and MA6800 perform as well as McIntosh separates. Both models incorporate
premium McIntosh technologies – including autoformers, Power Assurance, and
Silent Electromagnetic Switching – as well as several features that facilitate system
integration and expansion.
The patented McIntosh Power
Guard provides real-time clipping
protection without affecting power
output or sound quality.
a) test signal
b) overdriven amp without Power
Guard produces SEVERE clipping
c) overdriven amp with Power
Guard produces NO clipping
ab
c
MA6850

SILENT ELECTROMAGNETIC SWITCHING. In a conventional preamp, an input signal travels
to a switch, and then travels to the input circuitry. Unfortunately, the farther a signal must travel,
the more distorted it becomes. And this says nothing of what detritus a dirty switch can add to
the signal. McIntosh Silent Electromagnetic Switching literally brings the switch to the input.
The distortion-free switch consists of a glass tube containing oxygen-free gas and two signal
leads separated by mere thousandths of an inch. The tube sits in a multilayer copper coil and
the entire assembly is encased in shock-absorbent plastic. When DC voltage is applied to the
coil in response to a switching command, current flow creates a magnetic field that causes the
leads to bend and contact one another, completing the circuit. The inert gas eliminates corrosion
of the contacts, ensuring a low-resistance, distortion-free switch that never needs cleaning.
Another benefit is that non-selected inputs are truly “off,” eliminating potential sources of
interference.
PRECISION-TRIMMED VOLUME CONTROL. Level differences among channels in a stereo or
surround system compromise sound imaging. The left and right sections of McIntosh volume
controls are electronically trimmed for superior tracking.
ACTIVE VARIABLE LOUDNESS COMPENSATION. Typical loudness circuits apply a fixed
amount of compensation for listening at low volume. The MA6850 and MA6800 each have a
separate loudness control that applies compensation proportionately. When off, the loudness circuit
elements are completely removed from the signal path.
EXCLUSIVE MCINTOSH TONE CONTROLS. These offer ±12dB adjustments with fine resolution,
yet in the “flat” position are completely removed from the signal path.
CONTROL DATA OUTPUTS. To facilitate system integration, the MA6850 and MA6800 output
control data for source components. This allows remote operation of non-McIntosh components
either by direct connection to compatible data inputs or via a McIntosh Remote Translator.
REMOTE POWER CONTROL. This enables the MA6850/MA6800 to turn other McIntosh
system components on/off.
Featured Technologies (cont’d.)
About the MA6850/MA6800 Companion Products
The McIntosh products shown at right are logical companions for the MA6850/MA6800.
Separate literature is available. Check with your McIntosh dealer for any late additions. McIntosh
speaker systems are also covered in detail in separate literature.
MR7084 AM/FM Tuner. A natural companion for integrated amplifiers, the MR7084 tuner is a
thoroughly engineered broadcast monitor that reveals the upper limits of AM and FM performance.
MVS3 A/V Selector. The MVS3 connects to the VIDEO data output of the MA6850/MA6800 and
accommodates five additional A/V sources.
RCT3 Remote Translator. The Translator allows non-McIntosh components to be operated with
a McIntosh handheld remote or keypad. It connects to the data outputs on the MA6850/MA6800.
PC4 AC Power Controller. The PC4 provides five AC outlets (four switched) for turning non-
McIntosh components on and off automatically when it is connected to the power control output
of a Control Center or Integrated Amplifier.
HC1 Home Controller. The HC1 connects to the HOME data output and allows operation of other
devices such as lights and movie screens via a McIntosh handheld remote or keypad controller.
SCR3 Speaker Relay (not pictured). This connects to the main output of the MA6850/MA6800
to provide switching for two pairs of speakers. It also includes two switched AC outlets.
WK2 Keypad Controller or R649 IR Sensor. With switching for two pairs of speakers (using the
SCR3), the MA6850/MA6800 can feed music to a second zone, with operation via keypad or sensor.
MA6850/6800 Companions
MR7084 AM/FM TUNER
MVS3 A/V SELECTOR
RCT3 REMOTE TRANSLATOR
PC4 AC POWER CONTROLLER
HC1 HOME CONTROLLER
WK2 KEYPAD CONTROLLER
R649 IR SENSOR
The input selectors on McIntosh Control
Centers actually control state-of-the-art
silent electromagnetic switches.
lead
coil
sealed glass tube
circuit completes
when leads touch
lead
switching command causes DC voltage at coil

MA6850/MA6800 Integrated Amplifiers
2 x 150 watts (8/4/2 ohms)
Exclusive McIntosh output autoformers
Wide power bandwidth with ultra-low distortion
Exclusive McIntosh Power Assurance System:
Power Guard®clipping protection
Sentry Monitor®current protection
Thermal Cutout
DC Failure protection
Turn-On Delay
Soft Start inrush protection
Illuminated peak-responding meters
Silent electromagnetic switching
Precision-trimmed volume control with digital readout
Active Variable Loudness Compensation
Exclusive McIntosh tone controls
8 source selections (phono input on MA6800 only)
Switching for 2 pairs of speakers (with optional SCR3 Speaker Relay)
Independent listen and record selection
Dual processor loops
Accommodates more sources with McIntosh MVS3 A/V Selector
Control data output for source components
Remote power control
Remote operation of lights, screens, and drapes with McIntosh
HC1 Home Controller
Power and mute indications shown on multizone keypads
and sensors
Electronically regulated power supply with double-shielded transformer
Gold-plated input and output jacks
Fanless convection cooling
Modular construction with steel chassis
Glass front panel with illuminated nomenclature
Infrared remote control
Connector for external IR sensor or keypad controller
Headphone jack (MA6800 only)
RMS Power Output (8/4/2 ohms)
150W min. sine wave continuous
average power output per channel
from 20Hz to 20kHz with both
channels operating
Output Load Impedance
2, 4, or 8 ohms
Rated Power Band
20Hz to 20kHz
Peak Output Current
> 50 amperes
Total Harmonic Distortion
0.005% max. at any level from
250 milliwatts to rated power per
channel from 20Hz to 20kHz with
all channels operating
FEATURES
SPECIFICATIONS
McIntosh Laboratory, Inc., 2 Chambers Street, Binghamton, New York 13903
tel [phone] •U.S. toll-free (888) 979–3737 •fax [phone] •www.mcintoshlabs.com
S/N Ratio (A-Weighted)
Power amp: 110dB below
rated output
High level: 100dB below
rated output
Phono (MA6800 only): 90dB
below 10mV input (84dB)
Damping Factor
> 40
Input Impedance
High level: 22k ohms
Phono: 47k ohms, 65pf
Main in: 20k ohms
Power Guard®
Clipping is prevented and THD
does not exceed 2% with up to
14dB overdrive at 1kHz
Intermodulation Distortion
0.005% max. if instantaneous
peak power output does not
exceed twice the rated output
Dynamic Headroom
2.4dB
Frequency Response
20Hz to 20kHz, +0 / -0.5dB
Input Sensitivity
High level: 250mV for rated output
(1.4V at Main out)
Phono (MA6800 only): 2.5mV for
2.5V rated output (0.5mV IHF)
Main in: 1.4V for rated output
Maximum Input Signal
High level: 10V
Phono (MA6800 only): 90mV
Tone Controls
Bass and treble: ±12dB
Power Requirements
120V 50/60Hz, 6.5A
Dimensions (h x w x d)
inch: 7.062 x 17.5 x 20
cm: 17.9 x 44.5 x 50.8
knob clearance: 1.125" (2.9 cm)
Weight
70 lbs. (31.8kg) net
89 lbs. (40.4kg) shipping
0999.MA6850.5k.essecomm
MA6850
MA6800
MA6850 rear panel